Insole with heating element

ABSTRACT

An insole for a shoe includes at least a plate of thermoplastic material and a heating element. The thermoplastic plate is fully customizable. Fully customizable soles for shoes with heating elements, and a method for obtaining insoles or soles, especially for winter shoes are also described.

FIELD OF THE INVENTION

The present invention generally relates to footwear with heatingelements. In particular the invention concerns customizable insoles withheating elements, customizable soles for shoes with heating elements,and a method for obtaining those.

BACKGROUND OF THE INVENTION

Nowadays, popularity of winter sports and outdoor life is growing. Dueto an increasing need materials of winter outfits and boots especiallyfor winter conditions are developed. However, in cold environmentalconditions especially toes are particularly susceptible to losing bodytemperature and becoming uncomfortably cold. To provide insulation fromcold temperatures special winter shoes, such as snow boots, ski boots,slalom boots, some hiking boots and ice skates, are made especially forwintry conditions. Upper parts of winter shoes are usually made of clothor leather, soles are made of rubber materials, and shoe insoles andliners include padding, artificial fur, fur and/or other materials.

The insulating properties of regular winter shoe materials helps to keepthe toes warm in some circumstances, but in freezing conditions or whenone is staying a long period in cold conditions body temperature maybegin to fall and the insulation in the regular winter shoe may nolonger be adequate. In some circumstances, it is advantageous to providea heat source within a winter shoe, because once a person's feet becometoo cold, there is a risk of numbness, frostbite, or even hypothermia.

In addition, most of the people in the world population suffer from somesort of foot problems. Foot motion/gait problems reflect to soles,ankles, knees, hips, back, etc; that is why their treatment andprevention is particularly beneficial to the whole human well-being. Theload on feet in winter sports is higher than the weight of the body. Forexample, while skating the ground force may be about 1.5 to 2 timesone's body weight. Different (arch) support insoles are available forcorrecting the foot position. They have been designed to supportlongitudinal medial and lateral arch but without separately glued wedgesthey do not actually correct foot position. Wedging is a time-consumingand expensive process. The obtained result depends on the person doingthe task and still tends to be rather inaccurate. As another drawback,after gluing the wedges to the soles one cannot take a new mold withoutfirst removing the wedges.

There is, therefore, a need for a solution that provides warming fortoes, but also provides a perfect match to one's feet by a customizableinsole for a shoe or a shoe for minimizing the load on feet.

SUMMARY OF THE INVENTION

Now there has been invented an insole for a shoe, which insole comprisesa fully customizable thermoplastic material plate and a heating element,by which the above problems are alleviated. Various aspects of theinvention include an improved insole, sole for a shoe and a method formanufacturing an insole or sole, which are characterized by what isstated in the independent claims. Various embodiments of the inventionare disclosed in the dependent claims.

According to a first aspect, there is provided an insole for a shoe,which insole comprises at least a plate of thermoplastic material and aheating element.

According to an example embodiment the thermoplastic material is ABS,PVC, A-PET or PETG. According to an example embodiment, the insole has aheel area and a toe area and the plate covers at least partially theheel area and the heating unit covers at least partially the toe area.According to an example embodiment, the heating element is arranged tobe electrically connected to a battery unit by a wire for power supplyfor warming up the heating element. According to an example embodiment,there is a distance between the plate and the heating element. Accordingto an example embodiment, the insole comprises at least two layers,wherein the first layer is a surface layer and the second layer isformed from the plate and the heating element. According to an exampleembodiment, said thermoplastic material becomes plastic substantiallyunder 95° C. and above 45° C. According to an example embodiment, saidthermoplastic material becomes plastic substantially under 95° C. andabove 77° C.

According to a second aspect, there is provided a shoe comprising asole, which sole comprises at least a plate of thermoplastic materialand a heating element.

According to an example embodiment, said thermoplastic material becomesplastic substantially under 95° C. and above 45° C. According to anexample embodiment, said thermoplastic material becomes plasticsubstantially under 95° C. and above 77° C. According to an exampleembodiment, the thermoplastic material is ABS, PVC, A-PET or PETG.According to an example embodiment, the thermoplastic plate covers atleast the heel area of the sole and the heating unit covers at leastpartially the toe area of the sole. According to an example embodiment,the heating element is arranged to be electrically connected to abattery unit by a wire for power supply for warming up the heatingelement. According to an example embodiment, there is a distance betweenthe plate and the heating element. According to an example embodiment,the shoe is a skate, ski boot, winter shoe or slalom shoe.

According to a third aspect, there is provided a method formanufacturing an insole for a shoe comprising the steps of: providing afirst surface layer of the insole, wherein the first surface layer has aheel area and a toe area; covering at least partially the heel area ofthe first surface layer with a plate of thermoplastic material, coveringat least partially the toe area of the first surface layer with aheating element.

According to an example embodiment, the method further comprisesarranging a wire that is connected to the heating element on the otherside of the plate than the first surface such that the wire is guided onthe plate from the heating element towards the heel area of the firstsurface layer. According to an example embodiment, the method furthercomprises covering the first surface layer, the plate, the heatingelement and the wire by a second surface layer. According to an exampleembodiment, the thermoplastic material is ABS, PVC, A-PET or PETG.

DESCRIPTION OF THE DRAWINGS

In the following, various embodiments of the invention will be describedin more detail with reference to the appended drawings, in which

FIG. 1 shows a bottom view of an insole or sole manufactured accordingto an embodiment of the invention;

FIG. 2 shows an insole or sole manufactured according to an embodimentof the invention;

FIG. 3a shows a heating element according to an embodiment of theinvention;

FIG. 3b shows a heating element according to an embodiment of theinvention;

FIG. 3c shows a heating element according to an embodiment of theinvention;

FIG. 4 shows a heating unit and a power supply device for a heatingelement according to an embodiment of the invention;

FIG. 5 shows an example of a use a customizable insole with a heatingelement according to an embodiment of the invention; and

FIG. 6 shows a flowchart of a method for manufacturing a customizableinsole with a heating element according to an embodiment of theinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following, several embodiments of the invention will be describedin the context of a customizable i.e. personalizable insole with aheating element for a shoe, a shoe with customizable sole with a heatingelement and a method of manufacturing the customizable insole with aheating element for a shoe. It is to be noted, however, that theinvention is not limited to these. In fact, also the manufacturingmethod of sole for shoes may take place in a similar manner asmanufacturing insoles. In this line of thought, a shoe may be understoodto be any kind of footwear, boot or device intended to be worn on footin cold, but also in cool, conditions. The term insole in this contextcomprises also soles that are arranged to be fixed to the boots.

FIG. 1 shows a bottom view of an insole according to an embodiment ofthe invention. The upper layer 102 of the preform insole 100 isplaceable against the foot and the lower layer 103 is placeable againstthe shoe. Materials of these two layers may be selected among any commonmaterials used in insoles. For example, the lower layer 103 may beconstructed from a known material such as Rheluflex (trademark ofRhenoflex GmbH Ltd) comprising non-woven polyester as a carrier,ionomerresin-ethylvinylacetate blend as an extruded core, andEVA-Hotmelt as an adhesive.

The insole 100 further comprises at least one fully customizablethermoplastic plate 101, which is made of thermoplastic material andwhich material is fully customizable by heat. The thermoplastic plate101 is arranged to cover at least partially the heel area of the insole100, wherein the heel area comprises the heel and plantar arch area ofthe target person's foot. The thermoplastic plate 101 does not cover thetoe area of the insole 100. However, there could also be, for example,two or three or more thermoplastic plates in the insole 100.

The thermoplastic plate 101 may lay between the upper layer 102 and thelower layer 103. The thermoplastic plate 101 forms a part of the middlelayer. However, it is also possible that there is only one surface layerin addition to the thermoplastic plate 101, only the upper layer 102.The used thermoplastic material may be selected from a large group ofknown thermoplastics. A significant property for the thermoplastic isthe temperature, so-called glass transition temperature, where thethermoplastic becomes plastic and on the other hand turns back to solidform when the temperature is decreasing after shaping the insole. Theglass transition temperature is typically lower than polymer meltingtemperature. Therefore, one good temperature range for shaping thepreform may be between the glass transition temperature and the meltingtemperature. A possible temperature for the thermoplastic to becomeplastic is preferably somewhere under 95° C.and above 45° C.Advantageously the range is from 77° C. to 95° C. The temperature canalso be as high as 150° C. Suitable materials that become or are plasticwithin the preferred ranges are for example thermoplastic polyestersA-PET (Amorphous polyester terephthalate) and PETG (glycol-modifiedpolyethylene terephthalate, which is a copolyester), or such withessentially similar characteristics. Also e.g. ABS (acrylonitrilebutadiene styrene), PVC (polyvinyl chloride) can be used. The idea ofthe thermoplastic plate 101 is to able personalizing of the preforminsole 100 by forming the thermoplastic plate of the insole preformbased on foot information. The method and apparatus suitable for formingthe thermoplastic material is disclosed in PCT/F12009/050890application.

Thickness of the thermoplastic plate 101 may be selected so as toprovide reasonable support to the target person's foot when the layer isin a rigid (solid) state. Other characteristic required for thethermoplastic dictates that it should be rigid under the meltingtemperature. When warmed, the thermoplastic material will becomeflexible and therefore a mold with uniform properties (e.g. uniformpressing force) may be used, or a mold with non-uniform properties maybe used e.g. to achieve varying thickness. The thermoplastic materialmay be re-formed, if needed.

Between the upper layer 102 and the lower layer 103 of the insole 100 inthe vicinity of the thermoplastic plate 101 there is also a heating unit104. The heating unit 104 may be a material that is flexible andbreak-proof. The heating unit 104 comprises a heating element 105 thatmay be warmed up, for example, by using batteries as a power supply, forwarming the toe area, and a wire 106. The heating element 105 may be,for example, continuous stainless steel filament yarn. The heatingelement 105 may be a part of the same middle layer than thethermoplastic plate 101, but the heating element 105 is arranged tocover at least partially the toe area of the insole 100, wherein the toearea comprises the ball and toe area of the target person's foot.However, the thermoplastic plate 101 and the heating element 105 mayalso be in a different layer i.e. there may be at least one layerbetween them.

There may be a distance 107 between the heating element 105 and thethermoplastic plate 101. The distance 107 between the heating element105 and the thermoplastic plate 101 may be, for example, 1 cm or more.However, it is also possible that the heating element 105 and thethermoplastic plate 101 are next to each other so that there is nodistance between them.

The heating element 105 may be electrically connected to the wire 106that is electrically connectable to a battery unit (not shown). Thematerial of the wire 106 may be flexible and break-proof, for example, atear-resistant steel-reinforced cable. The wire 106 may extend betweenthe lower layer 103 and the thermoplastic plate 101 and may be guidedfrom the heating element 105 towards the edge of the heel area of theinsole 100. The wire 106 may come out from the insole 100 at the heelarea so that the wire 106 is suitable to be guided out from a shoe viathe back part of the shoe and through the opening of the shoe.

However, in addition to the thermoplastic plate 101 forming a firstmiddle layer with the heating element 105 (if the heating element 105 isin the same layer, they may also be in different layers), there may alsobe a second middle layer, or even more middle layers than two, forexample 3 or 4 between the upper layer 102 and the lower layer 103 andabove or under the first middle layer. The first middle layer comprisingthe thermoplastic plate 101 and the heating element 105 may form themiddle layer that only partially covers the area of the upper layer 102of the insole 100.

Reference number 108 indicates the center line of the perform insole100.

With reference to an embodiment shown in FIG. 2, there is disclosed anextra layer 201 between the upper layer 102 and the thermoplastic plate101 and the heating element 105 for providing comfort. The material ofthe extra layer 201 may be selected among any common materials used ininsoles. The thermoplastic plate 101 made of thermoplastic materialcovers laterally only a part of the insole 100. The thermoplastic plate101 extends lengthwise at least under the heel area and in lateraldirection advantageously almost to the whole width of the insole 100.Whereas the heating element 105 extends lengthwise at least under thetoe area and in lateral direction advantageously almost to the wholewidth of the insole 100.

The thermoplastic plate 101 may be designed to extend from under theheel to the under the plantar arch of the foot so that transverse archcan be supported. In addition, it is advantageous to keep some range atthe edge of the insole without the hard thermoplastic in case there isneed for little adjustment when the insole is placed in the shoe. Also,it is a benefit that the toe area of the insole 100 remains without thethermoplastic plate, because absence of thermoplastic material at thetoe area may enable natural movement of the foot during walking,running, skiing, skating or doing slalom skiing. However, it is alsopossible to design the plate larger and the heating element smaller, ifneeded, for example, it is possible that the heating element covers onlythe area under the toes. It should also be noted, that if thermoplasticmaterial is used above the heating element 105 i.e. if the thermoplasticplate 101 covers at least partially also the toe area of the insole 100so that the plate 101 is at least partially on the heating element 105,the heating element 105 may not warm up the toe area enough.

Components of insoles as shown in FIGS. 1 and 2 may also be used forshoes or soles for shoes.

FIGS. 3a, 3b and 3c show heating elements according to embodiments ofthe invention. The heating element 301 has a shape of star, the heatingelement 302 has a shape of circle and the heating element 303 has ashape of rectangle. The shape of heating element is not restricted toany shape, it may have any shape suitable to be warmed.

FIG. 4 discloses a heating system according to an embodiment of theinvention. The heating system 400 comprises at least a heating unit 401and a battery unit 403. The heating unit 401 comprises a heating element402 and a wire 403 that is arranged to electrically connect the heatingelement 402 and the battery unit 404.

The heating element 402 may be battery powered, because battery poweringallows it to be portable and lightweight enough to be comfortable. Thebattery unit 404 may comprise a battery or batteries that arerechargeable, for example, rechargeable nickel-metal hydride batterieswith 4.8 voltage and capacity of 1900 mAh or non-rechargeable batteries,for example, alkaline or lithium AA batteries with 4.8 voltage. Thebattery unit 404 may also comprise an indicator such as a led thatindicates a state of the batteries. The wire 403 and the battery unit404 may be releasably connected, so that the battery unit 404 can bereleased from the wire 403, for example, for charging. The wire 403 andthe battery unit 404 may be connected to each other by using anysuitable connecting elements. For example, the wire 403 may comprise afemale contact 406 and the battery unit 404 may comprise a male contact407 or other way around.

The battery unit 404 is connected to a fastening element 405 acting asfastening means for the battery unit 404. The fastening element 405 maybe for example a Velcro Strap that is suitable for releasably mountingthe battery unit 404 to user's ankle or calf. It should be noted thatthe battery unit 404 may be mounted in many possible locations includingbut not limited to on the shoes or on the target person's lower leg. Inaddition, it is possible to use other fastening element than Velcrostrap. It is possible to mount a stand to the shoe for the battery unitor use fastening screws, press fasteners or any other suitable fasteningmeans for mounting the battery unit to a shoe or lower leg of the targetperson. It may also be possible that battery unit 404 is an integratedpart of a shoe or it is embedded into a shoe.

The battery unit 404 may be released for charging, but it may also bepossible to charge the battery unit 404 while it is mounted to targetperson.

FIG. 5 shows an example of a use of a customizable insole with heatingelement according to an embodiment of the invention. The insole isarranged onto a sole of a slalom boot 500. A wire 501 is guided throughthe opening of the slalom boot 500 and connected to a battery unit 502.The battery unit 502 is releasably mounted onto the slalom boot 500 bytwo Velcro straps 503.

FIG. 6 shows a flowchart of a method for manufacturing a customizableinsole with heating element according to an embodiment of the invention.In stage 600, a first surface layer of the insole is provided, whereinthe first surface layer has a heel area and a toe area. In stage 601,the heel area and of the first surface layer is at least partiallycovered with a plate of thermoplastic material. In stage 602, the toearea of the first surface layer is at least partially covered with aheating element. The heating element is electrically connected to awire, wherein the wire is guided on the plate towards the heel area ofthe first surface layer.

Insoles or soles with at least one layer made of thermoplastic materialand heating elements are designed to go into boots and shoes to giveindividual support for feet and to keep toes and feet warm withsoothing, gentle heat even in the coldest of conditions.

It is obvious that the present invention is not limited solely to theabove-presented embodiments, but it can be modified within the scope ofthe appended claims.

The invention claimed is:
 1. A heating insole for a shoe, comprising: a first layer that includes a heel area and a toe area, a plate that covers the heel area, the plate being comprised of a heat-customizable thermoplastic material arranged to be formed, based on an individual user's foot, for personalized support of, at least partially, the heel area, and a battery-operated heating element that covers the toe area and is arranged to at least partially warm at least the toe area, wherein there is a distance, along a length of the first layer, between the plate and the heating element such that the plate and the heating element are non-overlapping.
 2. An insole according to claim 1, wherein the thermoplastic material is ABS, PVC, A-PET or PETG.
 3. An insole according to claim 1, wherein the heating element is arranged to be electrically connected to a battery unit by a wire for power supply for warming up the heating element.
 4. An insole according to claim 1, wherein the insole comprises at least two layers, wherein the first layer is a surface layer and the second layer is formed from the plate and the heating element.
 5. An insole according to claim 1, wherein said thermoplastic material becomes plastic substantially under 95° C. and above 45° C. for the heat-customization of the thermoplastic material, based on the individual user's foot, for the personalized support of, at least partially, the heel area.
 6. An insole according to claim 1, wherein said thermoplastic material becomes plastic substantially under 95° C. and above 77° C. for the heat-customization of the thermoplastic material, based on the individual user's foot, for the personalized support of, at least partially, the heel area.
 7. A shoe comprising a heating sole, comprising: a heel area and a toe area, a plate of heat-customizable thermoplastic material arranged to be formed, based on an individual user's foot, for personalized support of, at least partially, the heel area, and a battery-operated heating element arranged to at least partially warm at least the toe area, wherein there is a distance between the plate and the heating element such that the plate and the heating element are non-overlapping.
 8. A shoe according to claim 7, wherein the thermoplastic material is ABS, PVC, A-PET or PETG.
 9. A shoe according to claim 8, wherein the heating element is arranged to be electrically connected to a battery unit by a wire for power supply for warming up the heating element.
 10. A shoe according to claim 7, wherein said thermoplastic material becomes plastic substantially under 95° C. and above 45° C. for the heat-customization of the thermoplastic material, based on the individual user's foot, for the personalized support of, at least partially, the heel area.
 11. A shoe according to claim 7, wherein said thermoplastic material becomes plastic substantially under 95° C. and above 77° C. for the heat-customization of the thermoplastic material, based on the individual user's foot, for the personalized support of, at least partially, the heel area.
 12. A method for manufacturing an insole for a shoe comprising the steps of: providing a first surface layer of the insole, wherein the first surface layer has a heel area and a toe area; covering, at least partially, the heel area of the first surface layer with a plate of heat-customizable thermoplastic material arranged to be formed for personalized support of, at least partially, the heel area, and covering, at least partially, the toe area of the first surface layer with a battery operated heating element arranged to at least partially warm at least the toe area, wherein there is a distance between the plate and the heating element such that the plate and the heating element are non-overlapping.
 13. A method according to claim 12, wherein the method further comprises: arranging a wire that is connected to the heating element on the other side of the plate than the first surface such that the wire is guided on the plate from the heating element towards the heel area of the first surface layer.
 14. A method according to claim 13, wherein the method further comprises: covering the first surface layer, the plate, the heating unit and the wire by a second surface layer.
 15. A method according to claim 12, wherein the thermoplastic material is ABS, PVC, A-PET or PETG, and wherein the thermoplastic material becomes plastic substantially under 95° C. and above 45° C. for the heat-customization of the thermoplastic material, based on the individual user's foot, for the personalized support of, at least partially, the heel area. 